Embodiments relate to an earth leakage circuit breaker configured to protect a circuit.
In general, an earth leakage circuit breaker detects abnormal current in a circuit due to leakage or grounding and cuts off the circuit. Therefore, the earth leakage circuit breaker protects facilities and persons at a load end. That is, the earth leakage circuit breaker detects a peak current value from current sensed in the circuit and compares the peak current value with a predetermined current value. At this time, the peak current value may be detected from a fundamental wave component or a harmonic component of current. In addition, when the peak current value is equal to or greater than the predetermined current value, the earth leakage circuit breaker cuts off the circuit.
However, the earth leakage circuit breaker may malfunction. That is, the peak current value may be detected from the harmonic component of current according to the characteristics of a specific part in the earth leakage circuit breaker. Thus, even if abnormal current is not generated, the earth leakage circuit breaker may cut off the circuit based on the peak current value.